The endless belts used for moderate load power transmission application in automobiles, which are more commonly collectively termed fan belts, are constructed of a flexible, tear-resistant polymeric material and are manufactured in countless different sizes to accommodate the varying pulley sizes and spacings therebetween found in the vast number of different models of automobiles sold and driven in the United States and foreign countries. While these endless belts are quite durable, they nevertheless are subjected to a great deal of stress due to their high speed operation and consequently must be periodically replaced. Thus, for a garage to be able to meet the needs of its customers, it is necessary to stock a large number of differently sized belts. This presents a substantial inventory problem to the garage as these belts are of a fixed size and consequently a belt suitable for one make of automobile cannot generally be used in another unless the size requirements are the same. Unfortunately, this is not generally the case.
In addition to having to stock a large inventory of these belts, a garage mechanic must often expend a good deal of labor in securing the belt about the pulleys due to the limited flexibility inherent in such belts and the often encountered awkward positioning of the pulleys with respect to the automobile body presenting the mechanic with restricted access for mounting the belt on the pulleys.
The problems of fixed belt size and installation could be greatly relieved if the belt were either adjustable or of a construction whereby it could be readily assembled on site to the desired size for a particular application, e.g. in an auto repair garage by an auto repair person for a particular model of automobile. One solution to the problems of fixed belt size and installation is found in applicant's U.S. Pat. No. 4,031,766 wherein an adjustable belt is provided which can be assembled about the pulleys and thereby facilitate installation while obviating the need for an inventory of differently sized belts. That solution employs a belt having a male end of reduced diameter and a female end having a channel therein equal in length to the reduced diameter portion of the male end. To define a belt having the desired size, equal precalculated lengths are severed from both the male and female ends, and an adhesive is applied about the male end which is then inserted into the female end of the belt. To avoid any gaps which would otherwise weaken and imbalance the belt, these cuttings have to be carefully made to insure that the length of the reduced diameter portion of the male end is equal to the length of the channel in the female end.
An improvement to the above-described patented belt configuration is disclosed in applicant's U.S. Pat. No. Re. 33,389. In the improved structure, an outer length of flexible and durable belt material is provided with a centrally disposed channel extending therethrough and a flexible and durable cord is slidably disposed within the channel and extends the length thereof. An endless belt of the desired size is formed by cutting the length of belt material with the reinforcing cord contained therein to the desired length, pulling a portion of the cord from one end of the outer length of belt material and applying an adhesive to the exposed cord and the ends of the belt material. The exposed portion of the reinforcing cord is then inserted into the open channel in the other end of the outer length of belt material until the ends of the outer length of material are in an abutting relationship. As the reinforcing cord is of the same length as the outer length of material, the ends of the reinforcing cord will also be in an abutting relationship within the outer length of material. Upon setting of the adhesive, a durable endless belt of the desired size is formed. While such a belt construction and forming process retains the ease of installation and adjustability of the earlier patented construction, it eliminates the need for having to make to precise cuts during the belt forming process and provides the resultant belt with superior strength characteristics. However, it has been found that such a construction is relatively expensive due to the costs of forming a cylindrical longitudinal channel in the outer belt length. It would therefore be highly desirable to provide an endless belt forming process having these same improved characteristics but which reduces the cost of construction. The endless belt and forming processes disclosed herein achieve these results.